1. Field of the Invention
The present invention is directed to an apparatus for displacing a cable or piston by means of a hand operated lever and, more particularly, to a multiple linkage cable or piston displacement system.
2. Description of Related Art
It is well known within the bicycle and motorcycle industry to use lever operated brakes and clutches. Systems that use levers having a single pivot to pull on a cable are well known. Four-bar linkage systems have been attempted as well in cable displacement systems. However, considerable improvement is still needed in such systems to provide improved performance in the power ratio of lever movement to cable displacement. Moreover, there is a need for adjustable, hand actuated cable displacement systems in which the angle of operation of the lever can be adjusted to accommodate individual desires.
Japanese Utility Model Publication No. Sho 54-19004 discloses a four-bar linkage system utilized on a bicycle hand brake system. The links, however, are not positioned to significantly reduce potential lateral movement. That is, the lever can move laterally along the axis of the force application and away from its support bracket because the links in the mechanism are aligned essentially next to each other so that the lever must pivot around the two pivot points of the links on the support member.